High-Dose Statin Treatment Does Not Impair Aerobic Capacity Or Muscle Function In Older Adults. A Pilot Study: 965: June 2 10:30 AM - 10:45 AM

Hydroxy-Methylgluteryl-Co enzyme A (HMG CoA) reductase inhibitors (statins) are effective lip id-lowering agents, which reduce risk for coronary artery disease. Statin use is frequently associated with skeletal muscle complaints such as myalgia, cramping, and weakness. Blocking HMG-CoA reductase is known to reduce endogenous synthesis of coenzyme Q₁₀ (CoQ₁₀), an important co-factor for oxidative phosphorylation. A recent study reported significant reductions in skeletal muscle CoQ₁₀ levels and respiratory chain activities after 8 weeks of high dose simvastatin. It is not known whether decreased CoQ₁₀ is responsible for muscle symptoms or altered function.

PURPOSE: We tested the hypothesis that high-dose statin treatment would result in decreased work capacity in older men and women.

METHODS: Men and women (N=10), ages 55-76y (mean age: 66 ±6y), with LDL-cholesterol levels >130 mg/dL (mean= 161 ± 8 mg/dL, 4.2 ± 0.2 mmol/L) and not on cholesterol-lowering medications, received simvastatin (80 mg/day) for 12 weeks. Maximal oxygen consumption, high-intensity aerobic endurance, oxygen uptake kinetics, maximal strength, muscular power, and muscular endurance were measured at baseline and during week 12 of statin treatment. Creatine kinase (CK) was measured at rest and 24-h after completing exercise testing. Myalgia symptoms were assessed every 4 weeks.

RESULTS: As expected, statin treatment resulted in significant decreases in LDL- and total-cholesterol levels (p<0.01) with no changes in HDL-C or triglyceride levels. However, there were no significant changes in aerobic capacity, endurance, oxygen kinetics or any of the measures of muscular function in response to the1 2-week treatment. CK levels at rest were significantly higher at 12-wks but remained within normal ranges (108 ± 16 vs. 144 ±20 IU/L, p<0.05). No subject reported symptoms of myalgia, cramps, or weakness at any of the assessments.

CONCLUSION: High-dose simvastatin for 12 weeks did not result in myalgia symptoms or impaired exercise capacity in older individuals. These data suggest that the decreases in intramuscular CoQ 10 that have previously been observed in response to high dose statin treatment, may not be clinically relevant in terms of diminishing exercise capacity in individuals who do not experience myalgia symptoms.